In-situ Activation of a Highly Volatile and Thermally Stable Indium(III) Triazenide Precursor for Epitaxial Growth of Indium Nitride by Atomic Layer Deposition

Abstract

Indium nitride (InN) is characterised by its superb electron mobility making it a ground-breaking material for high frequency electronics. The difficulty of depositing highquality crystalline InN currently impedes its broad implementation in electronic devices. Herein, we report a new highly volatile and thermally stable In(III) triazenide precursor and demonstrate its ability to deposit high-quality epitaxial hexagonal InN by atomic layer deposition (ALD). The new triazenide precursor was found to sublime at 80 °C and thermogravimetric analysis showed single step volatilisation with an onset temperature of 145 °C and negligible residual mass. Strikingly, two temperature intervals were observed when depositing InN films. In the high temperature interval, the precursor underwent thermal decomposition inside the ALD reaction chamber to produce a more reactive indium compound whilst retaining self-limiting growth behaviour. Stochiometric InN films with very low levels of impurities were grown epitaxially on 4H-SiC. This new triazenide precursor now enables ALD of InN for semi-conductor applications.<br>